Refrigerating system



May 14, 1929. R. w. KRlTzER 1,712557 REFRIGERATING SYSTEM Filed Dec. 10, 192'6 41 I lNvENToR R. W /fR/rzff? A'nfoRNaYs Patented May 14, 1929.

UNITED sTATEs 1312,56? PATENT oFFlcs.,

IRCHARD W. KRITZER, OF CHICAGO, ILLINOIS, ASSIGNOR TO PEERLESS ICE ICHINE COMPANY, OF CHICAGO, ILLINOIS.

REFRIGEBATING SYSTEM.

Application filed December 10, 1926. Serial N'o. 154,004.

My invention relates to refrigerating systems, and more particularly to those systems in which the refrigerated medium is Circulated, such as apartment house refrigerating systems, and it consists in the combinations, constructions, and arrangements here'in described and claimed.

The operation of a refrigerating clrculating system has heretofore been fraught with the danger of freezing up the coolers in which the circulated medium is refrigerated, if for any reason the rate of flow of the refrigerated medium falls below certain limits.

The pressure of the circulated medium has different values and different conditions of operation, thus, whenever the system is at rest, the amount of pressure corresponds to the static head. Whenever the refrigerated medium is circulating, the pressure is that due to the static head plus the friction head. The friction head in any given system varies With the openingand closing of any valves through which the circulated medium passes, and also varies with the rate of flow of the circulated medium. i

For any given system in normal operation,

there is within limits af certain definite rate of flow with its consequent pressure. Any condition tending'to vary this rate of flow will make a change in the pressure of the circulated medium.

An objectof the invention is to provide a means whereby the refrigeration of the circulated medium is stopped Whenever the pressure of the circulated medium increases orI decreases between' certain'limits.

A. further object of the invention is to provide a system of the type described which is positive in action, which is not liable to get out of order, and which, therefore, can be depended upon to rprevent the freezing up of the coolers. i

Other objects and advantages will appear in the following specification, and the novel features of the mvention will be particularly pointed out in the ap ended claims. i

My invention is il ustrated in the accompanying drawings, forming part of this application, in which i lFigure 1 is a-diagrammatic view tem embodying my invention, and

Figure 2 is a sectional View through a pressure controlled switch;

The present invention involves the use of a primary refrigerating medium and a secof a sys- Aing preferaby a ondary refrigerating medium, the former begas and the latter a liquid which is cooled by the primary refrigerating medium.

In the drawings, 1 represents a motor which drives a compressor 2; the latter is connected by a pipe 3 with a condenser 4 in which a Cooling fluid, such as water, is circulated through an interior pipe 5. The condenser .communicates with a receiver 6 whichis connected by a pipe 7 with a cooler 8, an expansion Valve 9 being interposed in the pipe line 7. A return pipe 10 completes the circuit of the compressor, for the primary refrigerating medium.

The secondary refrigerating medium, which may be brine or other suitable liquid, is forced by a pump 11, driven by a motor' 12, through the pipe 13, which passes through the interior of the cooler 8, and which is connected-to the service pipe 14.: The latter leads to the refrigerators, not shown, and a return pipe 15 conveys the circulated medium back to the pump 11. Suitable valves, such as those? shown at 14a and 15a, respectively, are interposed at desired points for controlling the flow. The motor 12 may be connected to the leads 16 and 17 by the wires 16a and 17a, respectively. A manually operated switch 18 is provide-d for controlling the motor 12.

At 19 I have shown in general a pressure operated switch. In order to show how the system works, I have shown a switch in detail in Figure 2. In this figure there is a casing 20 having an inlet 21, the casing being provided with two compartments 22 and 23, respectively, each of which communicates with the inlet 21 by means of a common passage 24. A diaphragm 25 is held by a cover 26 between a central portion 26a and an outer' flanged portion 26. The cover has secured thereto brackets 27, having guide members 28 for plunger stems. One of the plungers 29 is arranged to enter an opening in the cover 20 and to engage the diaphragm 25, which may be supported underneath the plunger by a central boss 30. The plunger 31 is arranged to engage the diaphragm in the chamber 22 and this has a supporting boss 32. The plun er 29 is acted on by a spring 29E,having an ajusting screw 29, while the plunger 31 is acted on by a similar spring 31a and adjusting screw 31h. The plungers have slots .29 and 31, respectively. An extension 33 is provided upon which is pijvotally mounted an arm 34. This arm is acted on normally by a spring 35 and bears a. receptcale 36 containing mercury 37. VVires 38 and 39 lead into one end of the receptacle and when the mercury is in this end the terminals of the wires 38 and 39 are bridged so as to permit passage of current. A stop member 40 is provided on the cover 26. The interior of the casing 20 is in communication with the circulating pipe 14 by means of the pipe 41.

It will be understood that the foregoing description of the pressure control switch is given for the purpose of illustration only and that any other suitable pressure control switch might be used Without departing from the spirit of the invention, the invention lymg m 'the system of control rather than in the switch itself.

From the foregoing description of the various parts of the device, the operation thereof may be readily understoodn TWhen the 'manually operated switch 18 is closed, the

motor 12 will cause the operation of the pump 11 and the circulation of the brine through the pipe 14, through the refrigerators, not shown, and back by way of the pipe 15. Assuming that the compressor 2 is in operation, it will cause the compressed refrigerated gas to pass into the condenser 4, where the gas is cooled and liquefied by the fluid through the pipe 5. The liqueiied refrigerant falls'into the receiver 6 and thence passes by means of the pipe 7 and the expansion valve 9 to the cooler 8, where it absorbs heat from the circulated medium and changes into a gaseous state, from whence it passes by means of the pipe 10 again to the compressor. The pressure controlled switch is so adjusted that during the normal rate of fiow the plunger 31 is raised by means of the pressure on the diaphragm 25 sufficiently to permit the spring 35 to tilt the arm 34 into contact with the stop 40, thereby bridging the terminals of the wires 38 and 89 and thus energizing the motor 1, the current retur'ning to the lead wire 17 by the wire 42. The plunger 29 on the other hand is adjusted so that during the normal rate of flow of the secondary refrigerating medium, it remains substantially in its down- Ward position.

Consider now any condition such as a clogged circulating line, closed valves, etc., which tends to increase the pressure of the secondary refrigerating medium, This will tend to move the plunger 29 upwardly, and, since the plunger 31 must be in its upward position during this condition, the engagement of the arm 34 at the end of the slot 29 will cause the arm 34 to be tilted on its fulcrum so as to break the circuit through the wires 38.and 39, thus stopping the compressor motor 1. In case there should be an abnormal decrease of pressure, then the diaphragm 25 will retract so as to permit the loweriug of the plunger 31, which will engage the arm 34 and tilt the mercury switch so as to break the Circuit, thus stopping the compressor. Such a condition is shown in Figure 2.

The adjustment of the switch is done by manipulating the adjusting screws E29b and 31h, so that between certain limits of pressure of the refrigerated medium, the device will operate to stop the compressor and thereby obviate any danger of the freezing of the brine 01' other refrigerated medium, or of damage to the pipes or apparatus, which might result therefrom. In either case, after the compressor has stopped its operation, should pressure conditions in the circulated medium be restored to normal, then the mercury switch will bc tilted back into position so as to again close the circuit of the compressor motor, whereupon the latter will start up and the Cooling of the circulated medium will continue. Thus, as far as the cooling of the cireulated medium is concerned, the system is automatic.

I claim:

1. A refrigerating system, comprising means for circulating a refrigerant fluid, means for eirculating a liquid medium cooled by said refrigerant fluid, and means actuated by an abnormal change of pressure in the eirculated liquid medium for stopping the ('irculation of the refrigerant fluid.

2. A refrigerating system, comprising means for circulating a refrigerant fluid, means for circulating a liquid medium cooled by said refrigerant fluid, and means actuated by an abnormal change of pressure iu the circulated liquid medium for stopping the cireulation of the refrigerant fiuid, and for starting the circulation of the refrigerant fluid when the pressure of the circulated liquid medium is again normal.

3. A refrigerating system comprising means for circulating a refrigerant fiuid, means for circulatin a liquid medium cooled by said refrigerant uid, and means actnated by the Variation of pressure in the circulated liquid medium between predetermined limits for stopping the circulation of the refrigerant fiuid and for starting the circulation of the refrigerant fluid when the pressure of the circulated liquid medium is again normal.

4. A refrigerating system comprising means for circulating a refrigerant fiuid including a compressor and driving motor, means for circulating a liquid medium cooled by said refrigerant fluid, switch means actuated by an abnormal change of pressure in the circulated liquid medium for Stepping the motor and for starting the motor when the pressure of the circulated liquid medium is again normal.

RICHARD W. KRITZER. 

